Self-assembled films or layers on various substrates are well known in the art. These films or layers typically have functional groups (head groups) that bond to a cofunctional group on the substrate surface and organo groups that have some mutual attraction to neighboring molecules in the layer(s) or to the surface. The self-assembled films are used in various applications such as for medical and electrical use. In medical applications, the self-assembled films are used to form an interfacial layer between a titanium orthopedic implant and the surrounding body tissue. For electrical applications, the self-assembled films are useful for improving the performance of devices that incorporate organic-inorganic interfaces such as those found in organic light-emitting diodes. An example of a self-assembled organic layer is disclosed in U.S. Pat. No. 6,645,644 in which an organometallic compound such as a titanium or zirconium transition metal alkoxide is applied to a substrate such as a metal having a native oxide surface. The alkoxide groups react with the oxide groups forming a secure surface bond. The free or unreacted alkoxide groups are available for reaction with reactive groups such as acid groups in a subsequently applied layer.
Unfortunately, such organometallic coatings often have poor durability and are easily removed from many substrates, particularly polymer substrates such as polycarbonates and polysiloxanes.
It would be desirable to provide an organometallic coating derived from a transition metal alkoxide that has better durability and adhesion to various substrates, particularly polymer substrates.